How severe is CVE-2026-47265?

CVE-2026-47265 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-47265 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-47265?

CVE-2026-47265 affects Aiohttp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-47265?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-47265 have an EU (EUVD) identifier?

Yes. CVE-2026-47265 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34007.

When was CVE-2026-47265 published?

CVE-2026-47265 was published on 2026-06-02 and last updated on 2026-06-17.

CVE-2026-47265

CVE-2026-47265 is a high-severity vulnerability in Aiohttp with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-346.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.6
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34007
Weakness: CWE-346
Affected product: Aiohttp
Published: 2026-06-02
Last modified: 2026-06-17

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. Version 3.14.0 patches the issue. If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable.

Frequently asked questions

What is CVE-2026-47265?: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.14.0, cookies set with the `cookies` parameter on requests are sent after following a cross-origin redirect. If a developer uses the `cookies` parameter on a per-request basis then sensitive data might be leaked to an attacker if they manage to control a redirect. Version 3.14.0 patches the issue. If unable to upgrade, using a `Cookie` header in the `headers` parameter is not vulnerable.
How severe is CVE-2026-47265?: CVE-2026-47265 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-47265 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-47265?: CVE-2026-47265 affects Aiohttp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-47265?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-47265 have an EU (EUVD) identifier?: Yes. CVE-2026-47265 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34007.
When was CVE-2026-47265 published?: CVE-2026-47265 was published on 2026-06-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:*

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